1. Field of the Invention
The invention relates to pacing timers which are used by runners to provide information to the runner during the course of a race such as striding signal tones and visually displayed data.
2. Description of the Prior Art
The prior art shows a number of devices which provide repeating tones. See, for example, U.S. Pat. Nos. 3,789,402, 3,893,099, 3,882,480 and 3,540,344. These are metronome-like devices which simply generate a repeating tone signal at constant intervals. Before running, the runner can set the length of the interval, just as a musician would set the frequency of a metronome. In these prior art devices there is no recognition of the fact that a runner's stride length varies with the speed at which the runner is running and that the runner, in the course of a race, will change his speed and consequently stride length periodically. These prior art devices are directed to teaching a runner to develop a constant stride which is defined by an audible signaling tone and do not contemplate strides of various lengths during the course of a single run. If the runner should choose to change his speed during the course of a run, he must change the frequency of the tone signal by stopping to reset the device and the fact that the runner's stride length would change with this speed change would be ignored by these prior art devices. Thus, such repetitive tone devices have no capability of measuring a runner's distance accurately. Moreover, these devices are not responsive to the varied informational needs of a serious runner who may change speeds and strategies during the course of a race and will need records made of these changes so that overall goals will not be abandoned.
The devices taught in U.S. Pat. Nos. 3,901,121, 3,038,120 and 2,926,347 provide metronomes for musical training and are not related to the needs of a runner.
The devices taught in U.S. Pat. Nos. 3,119,610, 4,028,693, 2,457,968 and 3,846,704 are mounted adjacent to a track or swimming pool and do not respond to a runner's changing needs during the course of a race.
A further difficulty encountered by runners is that they lack critical information concerning their performance during a race. In distance races (over 5,000 meters), race officials may locate markers or individuals (with stop watches who also call out the total elapsed time if they were close enough to hear the starting gun) at specified intervals on the course, but this provides the runner with only the most minimal information and then, only at the split markers. But even with this information, it is quite difficult during the race for the runner to translate his elapsed time and distance information into other more usable information such as:
(1) how fast am I running now, as opposed to my overall average speed for the race?
(2) given the time remaining, how much must I increase my speed if I want to finish the race in a specific time?
(3) if I want to run the last eight miles at a rate of a mile in 6 minutes and 40 seconds, how fast do I stride, i.e. pick up one foot and put down the other?
(4) if I cannot run at such a rate, what will my final time be?
(5) if I get a "second wind", what will my final time be if I can keep up my new and slightly (but how much?) faster rate?
(6) how far have I run?
(7) what is the most consistent rate at which I may run for the entire race?
The principal problem with the current state of the art is that existing devices force the runner to adapt his style of running (the length of his stride or its frequency) to the particular device rather than having the device adjust itself to the runner. Thus, although some of the devices give an audible metronome-like tone signal to the runner indicating the frequency with which strides of predetermined length must occur if the runner wants to cover a predetermined distance in a predetermined length of time, these devices cannot adjust themselves to variations in the way a runner runs.
Because of fatigue, differences in terrain or temperature, stimulation from adjacent runners, blisters, pulled muscles, cramps or other aliments, need for water, or a myriad of other factors, no course of any significant distance can be run from start to finish using a uniform stride length or frequency. At the start of a race, a runner is never really sure how he will feel during the race. Although serious runners know that their best overall time will result from running splits which are as nearly equal in time duration as possible, they accomplish this by variations in stride length and rate of striding and not by running identical strides from beginning to end. Only if the course were absolutely flat, all in the sun or all in the shade, and no other variables affected the runner--an impossible situation--could a perfectly consistent race be run.
Another problem with existing devices is that they are based upon an incorrect belief about how people run. For example, Heywood (U.S. Pat. No. 3,789,402) says:
" . . . as a runner becomes fatigued, there is a tendency to modify his pace or stride length. For example, the fatigued runner tends to maintain a consistent stride length but take fewer steps. Alternatively, a runner may take the same number of steps over the running course but shorten the stride length." (emphasis added)
The results of my research contradict these statements. The Heywood Patent assumes that a runner has a single preferred stride length. My experiments have shown that a runner has an infinite number of preferred stride lengths, each one associated with a different speed. My experiments have also shown that stride length and frequency are directly related to each other; the faster a runner runs, the longer he strides and the more rapidly he strides. Conversely, the slower a runner runs, the shorter he strides and the more slowly he strides. Thus, the solution is not, as posited by Heywood, to train a runner to maintain a single frequency of striding by feeding him a metronome-like tone signal, because the runner will not comfortably be able to maintain the single frequency and still vary his stride length so as to change his speed. My solution is to adjust the tone signal to his preferred rate of running and at the same time have the device take into account the fact that as he speeds up or slows down, the length of his stride also changes. Then the device can show him on its screen how fast he is running, i.e. how fast he is covering ground. Two runners running side by side, i.e., covering ground at the same rate, are likely to be striding at different rates, one taking slower but longer strides, and the other shorter but faster strides and their stride rates and lengths may vary constantly in a race though they are running "shoulder to shoulder."
The existing state of the art does not take these running factors into account, nor can existing devices be adjusted to any of the variables.